<!doctype html><html lang dir=ltr><meta charset=utf-8><meta name=viewport content="width=device-width,initial-scale=1"><title>【第1周程序】Python 基本语法元素 | Python | Hui.Ke - Blog</title><meta name=generator content="Hugo Eureka 0.9.3"><link rel=stylesheet href=https://b.hui.ke/css/eureka.min.9cec6350e37e534b0338fa9a085bf06855de3b0f2dcf857e792e5e97b07ea905d4d5513db554cbc26a9c3da622bae92d.css><script defer src=https://b.hui.ke/js/eureka.min.fa9a6bf6d7a50bb635b4cca7d2ba5cf3dfb095ae3798773f1328f7950028b48c17d06276594e1b5f244a25a6c969a705.js></script>
<link rel=preconnect href=https://fonts.googleapis.com><link rel=preconnect href=https://fonts.gstatic.com crossorigin><link rel=preload href="https://fonts.googleapis.com/css2?family=Lora:wght@400;600;700&family=Noto+Serif+SC:wght@400;600;700&display=swap" as=style onload='this.onload=null,this.rel="stylesheet"'><link rel=stylesheet href=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/styles/vs.min.css media=print onload='this.media="all",this.onload=null' crossorigin><script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/highlight.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/bash.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/ini.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/json.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/php.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/python.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/shell.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/sql.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/x86asm.min.js crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/xml.min.js crossorigin></script>
<link rel=stylesheet href=https://b.hui.ke/css/highlightjs.min.2958991528e43eb6fc9b8c4f2b8e052f79c4010718e1d1e888a777620e9ee63021c2c57ec7417a3108019bb8c41943e6.css media=print onload='this.media="all",this.onload=null'><script defer type=text/javascript src=https://lib.baomitu.com/font-awesome/6.1.1/js/all.min.js></script>
<link rel=stylesheet href=https://cdn.jsdelivr.net/npm/katex@0.15.2/dist/katex.min.css integrity=sha384-MlJdn/WNKDGXveldHDdyRP1R4CTHr3FeuDNfhsLPYrq2t0UBkUdK2jyTnXPEK1NQ media=print onload='this.media="all",this.onload=null' crossorigin><script defer src=https://cdn.jsdelivr.net/npm/katex@0.15.2/dist/katex.min.js integrity=sha384-VQ8d8WVFw0yHhCk5E8I86oOhv48xLpnDZx5T9GogA/Y84DcCKWXDmSDfn13bzFZY crossorigin></script>
<script defer src=https://cdn.jsdelivr.net/npm/katex@0.15.2/dist/contrib/auto-render.min.js integrity=sha384-+XBljXPPiv+OzfbB3cVmLHf4hdUFHlWNZN5spNQ7rmHTXpd7WvJum6fIACpNNfIR crossorigin></script>
<script>document.addEventListener("DOMContentLoaded",function(){renderMathInElement(document.body,{delimiters:[{left:"$$",right:"$$",display:!0},{left:"$",right:"$",display:!1},{left:"\\(",right:"\\)",display:!1},{left:"\\[",right:"\\]",display:!0}]})})</script><script defer src=https://cdn.jsdelivr.net/npm/mermaid@8.14.0/dist/mermaid.min.js integrity=sha384-atOyb0FxAgN9LyAc6PEf9BjgwLISyansgdH8/VXQH8p2o5vfrRgmGIJ2Sg22L0A0 crossorigin></script>
<link rel=icon type=image/png sizes=32x32 href=https://b.hui.ke/icon_hub7ca0b5404c6d576559b2bd22c64b0e5_2009_32x32_fill_box_center_3.png><link rel=apple-touch-icon sizes=180x180 href=https://b.hui.ke/icon_hub7ca0b5404c6d576559b2bd22c64b0e5_2009_180x180_fill_box_center_3.png><meta name=description content="  程序设计练习题和考试题"><script type=application/ld+json>{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Docs","item":"https://b.hui.ke/docs/"},{"@type":"ListItem","position":2,"name":"Python","item":"https://b.hui.ke/docs/python/"},{"@type":"ListItem","position":3,"name":"【第1周程序】Python 基本语法元素","item":"https://b.hui.ke/docs/python/11/"}]}</script><script type=application/ld+json>{"@context":"https://schema.org","@type":"Article","mainEntityOfPage":{"@type":"WebPage","@id":"https://b.hui.ke/docs/python/11/"},"headline":"【第1周程序】Python 基本语法元素 | Python | Hui.Ke - Blog","datePublished":"2020-12-28T15:16:58+08:00","dateModified":"2022-04-06T14:48:58+08:00","wordCount":1789,"author":{"@type":"Person","name":"Hui.Ke"},"publisher":{"@type":"Person","name":"Hui.Ke","logo":{"@type":"ImageObject","url":"https://b.hui.ke/icon.png"}},"description":"\u003cp\u003e  程序设计练习题和考试题\u003c\/p\u003e"}</script><meta property="og:title" content="【第1周程序】Python 基本语法元素 | Python | Hui.Ke - Blog"><meta property="og:type" content="article"><meta property="og:image" content="https://b.hui.ke/icon.png"><meta property="og:url" content="https://b.hui.ke/docs/python/11/"><meta property="og:description" content="  程序设计练习题和考试题"><meta property="og:site_name" content="Hui.Ke - Blog"><meta property="article:published_time" content="2020-12-28T15:16:58+08:00"><meta property="article:modified_time" content="2022-04-06T14:48:58+08:00"><meta property="article:section" content="docs"><meta property="article:tag" content="Program"><meta property="og:see_also" content="https://b.hui.ke/docs/python/20/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/10/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/19/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/9/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/18/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/8/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/17/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/7/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/16/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/6/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/15/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/5/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/14/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/4/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/13/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/3/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/12/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/2/"><meta property="og:see_also" content="https://b.hui.ke/docs/python/1/"><script>!function(e){"use strict";!function(){var i,s=window,o=document,a=e,c="".concat("https:"===o.location.protocol?"https://":"http://","sdk.51.la/js-sdk-pro.min.js"),n=o.createElement("script"),r=o.getElementsByTagName("script")[0];n.type="text/javascript",n.setAttribute("charset","UTF-8"),n.async=!0,n.src=c,n.id="LA_COLLECT",a.d=n,i=function(){s.LA.ids.push(a)},s.LA?s.LA.ids&&i():(s.LA=e,s.LA.ids=[],i()),r.parentNode.insertBefore(n,r)}()}({id:"Jgb8aUbG5e3rqhrs",ck:"Jgb8aUbG5e3rqhrs",autoTrack:!0,hashMode:!0})</script><body class="flex min-h-screen flex-col"><header class="min-h-16 pl-scrollbar bg-secondary-bg fixed z-50 flex w-full items-center shadow-sm"><div class="mx-auto w-full max-w-screen-xl"><script>let storageColorScheme=localStorage.getItem("lightDarkMode");((storageColorScheme=="Auto"||storageColorScheme==null)&&window.matchMedia("(prefers-color-scheme: dark)").matches||storageColorScheme=="Dark")&&document.getElementsByTagName("html")[0].classList.add("dark")</script><nav class="flex items-center justify-between flex-wrap px-4 py-4 md:py-0"><a href=/ class="me-6 text-primary-text text-xl font-bold">Hui.Ke - Blog</a>
<button id=navbar-btn class="md:hidden flex items-center px-3 py-2" aria-label="Open Navbar">
<i class="fas fa-bars"></i></button><div id=target class="hidden block md:flex md:grow md:justify-between md:items-center w-full md:w-auto text-primary-text z-20"><div class="md:flex md:h-16 text-sm md:grow pb-4 md:pb-0 border-b md:border-b-0"><a href=/posts/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">Posts</a>
<a href=/docs/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 selected-menu-item me-4">Docs</a>
<a href=/categories/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">Categories</a>
<a href=/series/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">Series</a>
<a href=/tags/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">Tags</a>
<a href=/love/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">Love</a>
<a href=/about/ class="block mt-4 md:inline-block md:mt-0 md:h-(16-4px) md:leading-(16-4px) box-border md:border-t-2 md:border-b-2 border-transparent me-4">About</a></div><div class=flex><div class="relative pt-4 md:pt-0"><div class="cursor-pointer hover:text-eureka" id=lightDarkMode><i class="fas fa-adjust"></i></div><div class="fixed hidden inset-0 opacity-0 h-full w-full cursor-default z-30" id=is-open></div><div class="absolute flex flex-col start-0 md:start-auto end-auto md:end-0 hidden bg-secondary-bg w-48 rounded py-2 border border-tertiary-bg cursor-pointer z-40" id=lightDarkOptions><span class="px-4 py-1 hover:text-eureka" name=Light>Light</span>
<span class="px-4 py-1 hover:text-eureka" name=Dark>Dark</span>
<span class="px-4 py-1 hover:text-eureka" name=Auto>Auto</span></div></div></div></div><div class="fixed hidden inset-0 opacity-0 h-full w-full cursor-default z-0" id=is-open-mobile></div></nav><script>let element=document.getElementById("lightDarkMode");storageColorScheme==null||storageColorScheme=="Auto"?document.addEventListener("DOMContentLoaded",()=>{window.matchMedia("(prefers-color-scheme: dark)").addEventListener("change",switchDarkMode)}):storageColorScheme=="Light"?(element.firstElementChild.classList.remove("fa-adjust"),element.firstElementChild.setAttribute("data-icon","sun"),element.firstElementChild.classList.add("fa-sun")):storageColorScheme=="Dark"&&(element.firstElementChild.classList.remove("fa-adjust"),element.firstElementChild.setAttribute("data-icon","moon"),element.firstElementChild.classList.add("fa-moon")),document.addEventListener("DOMContentLoaded",()=>{getcolorscheme(),switchBurger()})</script></div></header><main class="grow pt-16"><div class=pl-scrollbar><div class="mx-auto w-full max-w-screen-xl lg:px-4 xl:px-8"><div class=lg:pt-12><div class="flex flex-col md:flex-row bg-secondary-bg rounded"><div class="md:w-1/4 lg:w-1/5 border-e"><div class="sticky top-16 pt-6"><div id=sidebar-title class="md:hidden mx-4 px-2 pt-4 pb-2 md:border-b text-tertiary-text md:text-primary-text"><span class=font-semibold>Table of Contents</span>
<i class='fas fa-caret-right ms-1'></i></div><div id=sidebar-toc class="hidden md:block overflow-y-auto mx-6 md:mx-0 pe-6 pt-2 md:max-h-doc-sidebar bg-primary-bg md:bg-transparent"><div class="flex flex-wrap ms-4 -me-2 p-2 bg-secondary-bg md:bg-primary-bg rounded"><a class=hover:text-eureka href=https://b.hui.ke/docs/python/>Python</a></div><ul class=ps-6><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/20/>期末测验</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/10/>【第9+周笔记】全课程总结与学习展望</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/19/>【第9周程序】计算生态纵览</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/9/>【第9周笔记】计算生态纵览</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/18/>【第8周程序】程序设计方法学</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/8/>【第8周笔记】程序设计方法学</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/17/>【第7周程序】文件和数据格式化</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/7/>【第7周笔记】文件和数据格式化</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/16/>【第6周程序】组合数据类型</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/6/>【第6周笔记】组合数据类型</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/15/>【第5周程序】函数和代码复用</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/5/>【第5周笔记】函数和代码复用</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/14/>【第4周程序】程序的控制结构</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/4/>【第4周笔记】程序的控制结构</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/13/>【第3周程序】基本数据类型</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/3/>【第3周笔记】基本数据类型</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/12/>【第2周程序】Python 基本图形绘制</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/2/>【第2周笔记】Python 基本图形绘制</a></div></li><li class=py-2><div><a class="text-eureka hover:text-eureka" href=https://b.hui.ke/docs/python/11/>【第1周程序】Python 基本语法元素</a></div></li><li class=py-2><div><a class=hover:text-eureka href=https://b.hui.ke/docs/python/1/>【第1周笔记】Python 基本语法元素</a></div></li></ul></div></div></div><div class="w-full md:w-3/4 lg:w-4/5 pb-8 pt-2 md:pt-8"><div class=flex><div class="w-full lg:w-3/4 px-6"><article class=prose><h1 class=mb-4>【第1周程序】Python 基本语法元素</h1><div class="text-tertiary-text not-prose mt-2 flex flex-row flex-wrap items-center"><div class="me-6 my-2"><i class="fas fa-calendar me-1"></i>
<span>2020-12-28</span></div><div class="me-6 my-2"><i class="fa-solid fa-pen-to-square me-1"></i>
<span>2022-04-06</span></div><div class="me-6 my-2"><i class="fas fa-clock me-1"></i>
<span>4 min read</span></div><div class="me-6 my-2"><i class="fas fa-folder me-1"></i>
<a href=https://b.hui.ke/categories/it/ class=hover:text-eureka>IT</a></div><div class="me-6 my-2"><i class="fas fa-th-list me-1"></i>
<a href=https://b.hui.ke/series/python/ class=hover:text-eureka>Python</a></div><div class="me-6 my-2"><i class="fa-solid fa-eye me-1"></i>
<span id=busuanzi_value_page_pv><i class="fa fa-spinner fa-spin"></i></span> Hits</div></div><p>  程序设计练习题和考试题</p><h2 id=温度转换>温度转换</h2><p>这是"实例"题，与课上讲解实例相同，请作答检验学习效果。</p><p>温度的刻画有两个不同体系：摄氏度（Celsius）和华氏度（Fahrenheit）。</p><p>请编写程序将用户输入华氏度转换为摄氏度，或将输入的摄氏度转换为华氏度。</p><p>转换算法如下：（C 表示摄氏度、F 表示华氏度）</p><p>C = ( F - 32 ) / 1.8</p><p>F = C * 1.8 + 32</p><p>要求如下</p><ol><li>输入输出的摄氏度可采用大小写字母 C 结尾，温度可以是整数或小数，如：12.34C 指摄氏度 12.34 度；</li><li>输入输出的华氏度可采用大小写字母 F 结尾，温度可以是整数或小数，如：87.65F 指华氏度 87.65 度；</li><li>输出保留小数点后两位，输入格式错误时，输出提示：输入格式错误；</li><li>使用 input() 获得测试用例输入时，不要增加提示字符串。</li></ol><h3 id=参考答案>参考答案</h3><pre><code class=language-python>##TempConvert.py
TempStr = input()
if TempStr[-1] in ['F', 'f']:
    C = (eval(TempStr[0:-1]) - 32)/1.8
    print(&quot;{:.2f}C&quot;.format(C))
elif TempStr[-1] in ['C', 'c']:
    F = 1.8*eval(TempStr[0:-1]) + 32
    print(&quot;{:.2f}F&quot;.format(F))
else:
    print(&quot;输入格式错误&quot;)
</code></pre><h3 id=答案解析>答案解析</h3><ol><li>将输入字符串转换为数字时使用 eval() 函数，不要用 int() 函数，因为输入的数字可能不是整数；</li><li>采用 {:.2f} 将输出数字变成两位小数点表示时，即使数学上该输出值是整数，也会按照小数方式输出，例如，转换后温度为 10 度，输出为 10.00。</li></ol><h3 id=最优解>最优解</h3><pre><code class=language-python>T = input()
if T[-1] in ['F','f']:
    print('{:.2f}C'.format((eval(T[0:-1])-32)/1.8))
elif T[-1] in ['C','c']:
    print('{:.2f}F'.format(eval(T[0:-1])*1.8+ 32))
else:
    print('输入格式错误')
</code></pre><h2 id=hello-world-i>Hello World I</h2><p>这是学习每种程序设计语言的第一个实例。</p><p>输出 Hello World，注意大小写。</p><h3 id=参考答案-1>参考答案</h3><pre><code class=language-python>print('Hello World')
</code></pre><h2 id=数字形式转换-i>数字形式转换 I</h2><p>获得用户输入的一个正整数输入，输出该数字对应的中文字符表示。</p><p>0 到 9 对应的中文字符分别是：零一二三四五六七八九</p><h3 id=参考答案-2>参考答案</h3><pre><code class=language-python>template = &quot;零一二三四五六七八九&quot;

s = input()
for c in s:
    print(template[eval(c)], end=&quot;&quot;)
</code></pre><h3 id=答案解析-1>答案解析</h3><p>print() 中增加 end="" 参数表示输出后不增加换行，多个 print() 可以连续输出。</p><h2 id=温度转换-ii>温度转换 II</h2><p>温度的刻画有两个不同体系：摄氏度（Celsius）和华氏度（Fahrenheit）。</p><p>请编写程序将用户输入华氏度转换为摄氏度，或将输入的摄氏度转换为华氏度。</p><p>转换算法如下：（C 表示摄氏度、F 表示华氏度）</p><p>C = ( F - 32 ) / 1.8</p><p>F = C * 1.8 + 32</p><p>要求如下</p><ol><li>输入输出的摄氏度采用大写字母 C 开头，温度可以是整数或小数，如：C12.34 指摄氏度 12.34 度；</li><li>输入输出的华氏度采用大写字母 F 开头，温度可以是整数或小数，如：F87.65 指华氏度 87.65 度；</li><li>不考虑异常输入的问题，输出保留小数点后两位；</li><li>使用 input() 获得测试用例输入时，不要增加提示字符串。</li></ol><h3 id=参考答案-3>参考答案</h3><pre><code class=language-python>##TempConvert.py
TempStr = input()
if TempStr[0] in ['F']:
    C = (eval(TempStr[1:]) - 32)/1.8
    print(&quot;C{:.2f}&quot;.format(C))
elif TempStr[0] in ['C']:
    F = 1.8*eval(TempStr[1:]) + 32
    print(&quot;F{:.2f}&quot;.format(F))
else:
    print() #不输入任何错误提示
</code></pre><h3 id=答案解析-2>答案解析</h3><p>这个实例扩展自实例1，请注意以下三点：</p><ol><li>将输入字符串转换为数字时使用 eval() 函数，不要用 int() 函数，因为输入的数字可能不是整数；</li><li>采用 {:.2f} 将输出数字变成两位小数点表示时，即使数学上该输出值是整数，也会按照小数方式输出，例如，转换后温度为 10 度，输出为 10.00；</li><li>TempStr[1:] 表示字符串除首字符外的所有字符。</li></ol><h3 id=最优解-1>最优解</h3><pre><code class=language-python>T=input()
if T[0] in ['F','f']:
    print('C{:.2f}'.format((eval(T[1:])-32)/1.8))
elif T[0] in ['C','c']:
    print('F{:.2f}'.format(eval(T[1:])*1.8+32))
else:
    print()
</code></pre><h2 id=货币转换-i>货币转换 I</h2><p>人民币和美元是世界上通用的两种货币之一，写一个程序进行货币间币值转换，其中：</p><p>人民币和美元间汇率固定为：1 美元 = 6.78 人民币。</p><p>程序可以接受人民币或美元输入，转换为美元或人民币输出。人民币采用 RMB 表示，美元 USD 表示，符号和数值之间没有空格。</p><p>注意：</p><ol><li>这是一个 OJ 题目，获得输入请使用 input()；</li><li>不提示输出格式错误，结果小数点后保留两位。</li></ol><h3 id=参考答案-4>参考答案</h3><pre><code class=language-python>CurStr = input()
if CurStr[:3] == &quot;RMB&quot;:
    print(&quot;USD{:.2f}&quot;.format(eval(CurStr[3:])/6.78))
elif CurStr[:3] in ['USD']:
    print(&quot;RMB{:.2f}&quot;.format(eval(CurStr[3:])*6.78))
</code></pre><h3 id=答案解析-3>答案解析</h3><p>这个代码是实例 1 的一个扩展，注意以下 3 点：</p><ol><li>eval()函数将字符串转换成数字，不能省略；</li><li>== 表示 &ldquo;等于&rdquo;，in 表示成员包含，对于这个题目，由于只允许输入采用全大写方式，两种方法均可；</li><li>:.2f 输出小数点后两位。</li></ol><h2 id=hello-world的条件输出>Hello World的条件输出</h2><p>获得用户输入的一个整数，参考该整数值，打印输出"Hello World"，要求：</p><p>如果输入值是 0，直接输出"Hello World"</p><p>如果输入值大于 0，以两个字符一行方式输出"Hello World"（空格也是字符）</p><p>如果输入值小于 0，以垂直方式输出"Hello World"</p><h3 id=参考答案-5>参考答案</h3><pre><code class=language-python>n = eval(input())
if n == 0:
    print(&quot;Hello World&quot;)
elif n &gt; 0:
    print(&quot;He\nll\no \nWo\nrl\nd&quot;)
else:
    for c in &quot;Hello World&quot;:
        print(c)
</code></pre><h2 id=数值运算>数值运算</h2><p>获得用户输入的一个字符串，格式如下：</p><p>M OP N</p><p>其中，M 和 N 是任何数字，OP 代表一种操作，表示为如下四种：+, -, *, /（加减乘除）</p><p>根据 OP，输出 M OP N 的运算结果，统一保存小数点后2位。</p><p>注意：M 和 OP、OP 和 N 之间可以存在多个空格，不考虑输入错误情况。</p><h3 id=参考答案-6>参考答案</h3><pre><code class=language-python>s = input()
print(&quot;{:.2f}&quot;.format(eval(s)))
</code></pre><h3 id=答案解析-4>答案解析</h3><p>体会 eval() 函数的作用，在编程中用处很大。</p><h3 id=最优解-2>最优解</h3><pre><code class=language-python>print(&quot;{:.2f}&quot;.format(eval(input())))
</code></pre></article><div class=my-4><a href=https://b.hui.ke/tags/program/ class="inline-block bg-tertiary-bg text-sm rounded px-3 py-1 my-1 me-2 hover:text-eureka">#Program</a></div><div class=py-2><div class="my-8 flex flex-col items-center md:flex-row"><a href=https://b.hui.ke/authors/hui.ke/ class="md:me-4 text-primary-text h-24 w-24"><img src=https://b.hui.ke/bagua.webp class="bg-primary-bg w-full rounded-full" alt=Avatar></a><div class="mt-4 w-full md:mt-0 md:w-auto"><a href=https://b.hui.ke/authors/hui.ke/ class="mb-2 block border-b pb-1 text-lg font-bold"><h3>Hui.Ke</h3></a><span class="block pb-2">❤ Cyber Security | Safety is a priority.</span>
<a href=mailto:3199731997@qq.com class=me-2><i class="fas fa-envelope"></i></a>
<a href="https://wpa.qq.com/msgrd?v=3&uin=3199731997" class=me-2><i class="fab fa-qq"></i></a>
<a href=/images/aixinxianquan.webp class=me-2><i class="fab fa-weixin"></i></a></div></div></div><div class="-mx-2 mt-4 flex flex-col border-t px-2 pt-4 md:flex-row md:justify-between"><div><span class="text-primary-text block font-bold">Previous</span>
<a href=https://b.hui.ke/docs/python/2/ class=block>【第2周笔记】Python 基本图形绘制</a></div><div class="mt-4 md:mt-0 md:text-right"><span class="text-primary-text block font-bold">Next</span>
<a href=https://b.hui.ke/docs/python/1/ class=block>【第1周笔记】Python 基本语法元素</a></div></div><div id=valine-comments class=mt-4></div><script defer src=https://cdn.jsdelivr.net/npm/valine@1.4.16/dist/Valine.min.js integrity=sha384-e0+DNUCJo75aOAzHQbFWYBCM9/S4f0BhRJXvEgbE3mMS85RM20MSSGStHuNdY2QK crossorigin></script>
<script>document.addEventListener("DOMContentLoaded",function(){new Valine({el:"#valine-comments",appId:"BQnVqWIiq78AdqwyhvBVAa3y-MdYXbMMI",appKey:"RKg5By312YjM8rU6WkkfK9IN",recordIP:"true",serverURLs:"https://l.hui.ke",visitor:"true"})})</script></div><div class="hidden lg:block lg:w-1/4"><div class="bg-secondary-bg
prose sticky top-16 z-10 hidden px-6 py-4 lg:block"><h3>On This Page</h3></div><div class="sticky-toc
border-s
hidden px-6 pb-6 lg:block"><nav id=TableOfContents><ul><li><a href=#温度转换>温度转换</a><ul><li><a href=#参考答案>参考答案</a></li><li><a href=#答案解析>答案解析</a></li><li><a href=#最优解>最优解</a></li></ul></li><li><a href=#hello-world-i>Hello World I</a><ul><li><a href=#参考答案-1>参考答案</a></li></ul></li><li><a href=#数字形式转换-i>数字形式转换 I</a><ul><li><a href=#参考答案-2>参考答案</a></li><li><a href=#答案解析-1>答案解析</a></li></ul></li><li><a href=#温度转换-ii>温度转换 II</a><ul><li><a href=#参考答案-3>参考答案</a></li><li><a href=#答案解析-2>答案解析</a></li><li><a href=#最优解-1>最优解</a></li></ul></li><li><a href=#货币转换-i>货币转换 I</a><ul><li><a href=#参考答案-4>参考答案</a></li><li><a href=#答案解析-3>答案解析</a></li></ul></li><li><a href=#hello-world的条件输出>Hello World的条件输出</a><ul><li><a href=#参考答案-5>参考答案</a></li></ul></li><li><a href=#数值运算>数值运算</a><ul><li><a href=#参考答案-6>参考答案</a></li><li><a href=#答案解析-4>答案解析</a></li><li><a href=#最优解-2>最优解</a></li></ul></li></ul></nav></div><script>window.addEventListener("DOMContentLoaded",()=>{enableStickyToc()})</script></div></div></div></div></div><script>document.addEventListener("DOMContentLoaded",()=>{hljs.highlightAll(),changeSidebarHeight(),switchDocToc()})</script></div></div></main><footer class=pl-scrollbar><div class="mx-auto w-full max-w-screen-xl"><div class="text-center p-6 pin-b"><script async src=/js/click.js></script><div id=poem_ip></div><script type=text/javascript>jinrishici.load(function(e){tags.innerHTML=e.data.matchTags})</script><div><span id=timeDate>载入年天数...</span><span id=times>载入时分秒...</span>
<script async src=/js/duration.js></script></div><a href=https://www.foreverblog.cn/go.html target=_blank><img src=https://img.foreverblog.cn/wormhole_4_tp.gif alt style=display:inline-block;width:auto;height:32px title=穿梭虫洞-随机访问十年之约友链博客></a><p class="text-sm text-tertiary-text"><script async src=//busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js></script>本站总访问量 <span id=busuanzi_value_site_pv></span> 次
&#183; 您是本站的第 <span id=busuanzi_value_site_uv></span> 个小伙伴</p><script async src=/js/tab.js></script></div></div></footer></body></html>